


The Cut That Never Heals

by Sincestiel



Series: Tumblr Prompts [7]
Category: Supernatural
Genre: Anal Sex, Dark, Demon Dean, Dirty Talk, Exhibitionism, Frottage, Hand Jobs, Incest, Kinda, M/M, Masturbation, Mildly Dubious Consent, Tumblr Prompt, Voyeurism
Language: English
Status: In-Progress
Published: 2016-11-16
Updated: 2016-11-17
Packaged: 2018-08-31 10:06:37
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 4,251
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/8574130
Author URL: https://archiveofourown.org/users/Sincestiel/pseuds/Sincestiel
Summary: Sam feels sweat drop from Dean’s face onto his back.  It’s a steady dripthrustdripthrustdrip.  And that’s what Sam focuses on.  Tries to look anywhere but at the blue eyes watching them from across the room.  Anything he can do to take himself out of this moment.  He has to hold on.  Can’t come until Dean allows it.  If he comes too soon, then Cas won’t be allowed.





	1. Chapter 1

**Author's Note:**

> The second fic in as many days with voyeur!Castiel. Sorry about that. But I got a prompt and it was scrumptious. 
> 
> prompt: Wincestiel with dominant MarkofCain!Dean (anal, top Dean, bottom Sam, voyager Castiel), please?
> 
> I went Demon!Dean instead. But that's only mentioned once, so maybe you can ignore that? It was so hard not to go really dark with this. But I managed to just make Dean a mild asshole instead of going full throttle with it.
> 
> And I so badly want to write a second part to this with some Sastiel loving because Castiel deserves it. So that might possibly be in the works.
> 
> Again, all mistakes are my own.

“Yeah, Sammy, that’s right,” Dean grunts his fingers digging into the flesh covering Sam’s hips as he pulls Sam’s large body back to meet his thrusts, “Take it just like that for me. So tight, Sammy.”

Sam feels sweat drop from Dean’s face onto his back. It’s a steady _dripthrustdripthrustdrip._ And that’s what Sam focuses on. Tries to look anywhere but at the blue eyes watching them from across the room. Anything he can do to take himself out of this moment. He has to hold on. Can’t come until Dean allows it. If he comes too soon, then Cas won’t be allowed.

“He looks good, doesn’t he, Cas? My baby brother presenting himself all wet and open for me. Takes it like a cheap whore too.”

At first Castiel doesn’t answer and Sam’s heart rate doubles. Now is not the time to revolt. Not when Sam’s cock is dangling hard and heavy between his legs, leaking everywhere and Dean’s dick is riding right against his prostate on every thrust. Not when Dean has promised them both release as long as they can be good. And Mark of Cain or not, Dean keeps his promises.

“He’s beautiful,” Cas finally says when Dean’s hips start to slow and Sam sighs in relief when the pace only falters momentarily.

“Yeah, he is. My beautiful little baby brother. Taking my cock like it’s his only purpose in life,” Dean says it thoughtfully and Sam’s not even sure if the idea makes him nervous as hell or hot as fuck. Dean could do it too, if he wanted. He could order Sam to stay right here, open and ready and willing for the rest of his fucking life and Sam would agree. He’s waited too long to have this and he doesn’t plan on giving it up for anything. And if the fact that Dean had to go demon for him to get it tries to assert itself, Sam just stomps it down. Dean has strong morals for a man willing to break every law. That’s all. It’s not that Dean _doesn’t_ want this. Hell, it’s Dean who keeps dragging them all into this. And it’s Dean who rules with a damn iron fist.

One of Dean’s hands moves to Sam’s head, tangles in his hair. And then Sam is being pulled up, the backs of his thighs resting over the tops of Dean’s. His legs fall wide open, affording Cas the best view he possibly can. Because that’s what he’s supposed to do. Make sure he’s putting on a good show for Cas. Sam moans and bites his lip at the change in angle and finally meets Castiel’s eyes. They’re dark and hooded. His erection is standing proud and tall between his legs, but he’s not touching it. He can, if he wants, but Cas isn’t exactly a pro in the stamina department. Dean says he’s greedy. Sam just thinks they haven’t done a good job teaching him. He doesn’t know how to drag the pleasure out. Dean never touches him. Never lets Sam touch him. So Cas only knows one speed. And once he gets his hand on himself, it’s all over.

Sam can’t look Cas directly in the eye for too long. The sadness that’s settled heavily there in the last few weeks since they started this is too much to bear. And Sam gets it. He really does. While this, Dean fucking Sam like they’re rabbits, is something Sam would never have had without the Mark, it’s a hindrance to Cas. Without the Mark, Cas would have been the one in Dean’s bed. And it wouldn’t have been anything like this. Wouldn’t have left Cas aching and hollow like it almost does Sam.

“Chin up, buttercup,” Dean cuts into Sam’s thoughts, bringing him back to the moment, “Come on, baby. Ride me. Show Cas how good you are. Let him see that gorgeous cock of yours wave around while you bounce on my lap.”

Sam whines when Dean’s hold on his hair tightens. It’s a threat. Sam’s never pushed hard enough to find out just how Dean might punish him. But he can’t imagine it would be anything he wouldn’t like. Until Dean Sam wasn’t very big on spanking, but when Dean does it, Sam arches and writhes and begs for more. So there’s no punishment Sam can fathom that he wouldn’t like. Unless Dean just refuses to touch him at all. And the thought that Dean might very well do that, he knows Sam well enough after all, kicks Sam into gear.

He uses all the strength he has left in his wobbling legs, and lifts himself almost all the way off Dean’s cock before dropping down again. Wash, rinse, repeat. And goddamn it’s glorious. See, the thing is, Dean’s dick? It’s fucking huge. Long and thick and it takes Sam’s breath every time the entire length fills him. And it’s perfect because apparently, on top of being a slut for Dean, he’s a damn size queen too.

“Doing good, Sammy. Feels so good, baby. ‘M close,” Dean murmurs in Sam’s ear, his fee hand sliding up Sam’s torso to tweak a nipple. “You gonna hold out for me? Because you can come if you really want. Leave Cas high and dry. We’ll make him sit naked in the chair for the rest of the night. Watch his pretty cock deflate. Whatcha think, Sammy?”

Part of Sam wants to give in because it’s what Dean wants. Sam knows. There’s something about Cas that sets Dean on edge. Probably the fact that he’s been in love with him forfuckingever. But Dean makes this so much harder on Cas than he does on Sam. Sam doesn’t like being nothing but a fucktoy even if his body always responds favorably. He hates not having any part of Dean but his dick. Misses the way Dean used to care about him. But Cas? God. Cas might as well be sitting across from a stranger now. And Sam knows it cuts him deeper because they were so close to finally crossing that line. And now Dean is this and Cas is watching what he thought would be his future crumble at his feet.

Sam can’t do him that way, even if it would earn him Dean’s praise, “I can wait,” Sam grates out, still lifting and falling on Dean’s cock like it’ll be his salvation.

“What if his orgasm meant you couldn’t have yours? What then, Sammy? Would you let him come instead? Curl up here at the foot of my bed with your hole leaking my come everywhere and your cock and balls throbbing?” Dean says it like he’s actually considering it. Like he wants nothing more than to see one of them go without. And he doesn’t much care which one it is. It sends an electric thrill skittering down Sam’s spine and he’s so close to shooting everywhere. But he knows Dean. Even this Dean. He’s already promised. And he won’t go back on it as long as they hold up their end of the bargain. So Sam just has to hold on and not let Dean’s forked tongue drive him over the edge.

“Would you cry for me, Sammy? Snivel and whimper all night because your big brother didn’t jerk you off after he fucked you? Bet I’d wake up to you humping my foot, wouldn’t I?”

Sam shivers, head to toe and he’s so sure he’s going to blow. But then, with no warning, Dean slams his hips up and pulls Sam tight against him. A broken, “Sammy,” punches out of him, and Sam feels him pulse and jerk inside his body. Dean comes and comes and Sam’s cock, seemingly hardwired to perk up at Dean’s pleasure, threatens to spill over. But Sam catches Cas’ gaze again and reminds himself why he has to hold on.

And god, Cas looks so out of it watching Dean lose himself in the throes of ecstasy. His hands are gripping the sides of the chair so hard Sam thinks he might break it. And his lip is caught between his teeth. He’s making aborted little thrusts upward, seeking a friction he’s not going to find. Fuck. In moments like this, with Cas so utterly destroyed and Dean on the verge of sated… Well. Sometimes Sam wishes Dean would let him touch Cas if nothing else. Because Sam could make it so good for him. And he deserves it.

“Go ahead, Cas,” Dean says finally, voice too put together for someone who just came like a goddamn freight train. But then Dean’s hand wraps around his cock and Sam stops thinking about anything other than coming as soon as he possibly can.

Dean jerks him perfunctorily, the heat and dirty talk left behind now that Dean has found his release. But that’s okay. Because he can see Cas and Cas is staring right at him. For once, his eyes don’t flick to Dean at all. And when Cas comes, Sam would swear he mouths Sam’s name rather than Dean’s. Maybe that’s what pushes Sam over. Or maybe it’s the way Dean presses against his slit on the upstroke. But Sam grunts and spills over Dean’s fist a few seconds after Cas coats his own stomach in semen.

Sam cleans Dean up, fetching a washcloth on unsteady legs. Cas cleans himself and then disappears. He slinks out while Sam is tending to Dean’s crotch. When Sam turns around both he and his clothes are gone and Sam figures he’ll end up in Sam’s bedroom. That’s usually where he goes after they do this. Sam smells him all over his covers the next day. But Sam doesn’t complain. Won’t ever. Cas should be able to take comfort somewhere. 

Sam ends up at the foot of Dean’s bed, like always. It’s not comfortable. Not by a long shot. But, on nights like tonight, Sam can’t leave him. And while Dean refuses to allow anything even remotely resembling snuggling, he allows this. Probably because it feels like deference. Or defeat. But it’s neither. It’s just Sam loving his brother the best he can.


	2. Chapter 2

**Notes for the Chapter:**

> Here's the promised part two. A third part will be coming as well, though it might be a few days.
> 
> This part is only Sastiel in a physical sense. The next will be Wincestiel.
> 
> All mistakes are my own.
> 
> And, hey, seriously, thanks for reading. I really appreciate it!

“You okay, Cas?” Sam asks, dropping next to Castiel on his bed. Cas spends a lot of time lounging in Sam’s room now. Sam thinks it’s mostly to avoid Dean but maybe also because the weeks they spent keeping Dean occupied while other people were looking for a cure made him feel safer in Sam’s presence than Dean’s. Sam has sort of, by default and circumstances that feel like they were beyond their control – but probably weren’t, become Cas’ safe space.

Dean apologized on an almost endless loop for the first few days after they cured him and got rid of the Mark. And he’s still skittish like a baby colt, jumps every time one of them touches him. So Cas stopped putting himself in touching range and Sam knows he does it because it hurts to watch Dean flinch at contact he used to crave. Sam hasn’t stopped though. He’s different. He puts himself in Dean’s way. Makes Dean touch him even if it’s just in passing and completely accidental. Sam is determined to force Dean’s hand, one way or the other. He’ll either have to admit he wants Sam or he’ll have to break Sam’s heart. At this point Sam just wants Dean to crack, whichever way it goes. The limbo they’re all living in is killing them.

“I’m fine, Sam,” Cas answers, lifting his gaze from the book he’s reading but the smile he offers Sam doesn’t reach his eyes. “And yourself? Are you okay?”

Sam shrugs and then shakes his head, but he returns Cas’ smile and he thinks his is probably less brittle. Cas has had it so much harder than him the last few months. Because even if Dean never lays a hand on either of them again, at least Sam got to have him. Cas never even got to touch him. 

Cas seems to come to some sort of conclusion and he shuts the book in his lap before dropping it gently to the floor. He reaches up to loosen his tie and then pulls it over his head and tosses it toward the corner where his trench coat is crumpled in a chair, his shoes resting under it. His suit jacket gets the same treatment and then he’s just in a white button down and slacks.

Sam isn’t sure where Cas is going with this, but when he turns the bedside lamp off and reaches out, Sam goes willingly. The gasp Cas releases when Sam pulls him tight against his chest, dropping a soft kiss to the top of his head, makes Sam’s heart skip a beat. Sam leans back against the headboard, pulling Cas’ smaller frame with him. He ends up with Cas’ arms wrapped around his waist and his own over them, one at the small of Cas’ back and the other on his neck, fingertips just grazing the hair at his nape. Cas’ head rests against’ Sam’s chest, ear firmly planted right over Sam’s heart.

For several long minutes they don’t speak at all. Sam listens to and finds himself matching Castiel’s breathing. And Cas keeps his ear right next to Sam’s heart, presumably listening to it pound against Sam’s ribcage. Because that’s what it feels like to Sam, like his heart might just beat right out of his chest. It’s been so damned long since he’s held someone like this. Even longer since someone held him back with equal strength and need. He probably likes it more than he should, more than he has any right to at any rate.

“I’m so sorry, Sam,” Cas whispers, arms pulling tighter around Sam’s midsection.

“What do you have to be sorry about, Cas?” As far as Sam is concerned, Castiel is the least to blame for the current stalemate they seem to be experiencing. Castiel didn’t _do_ anything. Sam is the one who kept stalling. He kept dragging everything out even though he knew how to cure Dean even if he didn’t know how to remove the Mark. Sam kept them all tied up in each other much longer than they had to be. But he couldn’t give it up. Not when he finally had exactly what he’s always wanted. If Castiel hadn’t practically begged Sam to start treating Dean, they’d still be all tangled up.

“I wasn’t strong enough. And I know you were… you wanted… but I couldn’t. It hurt too much,” Cas admits, voice low and sad and Sam’s gut twists because it’s his fault Cas might lose Dean. It’s his fault they were all screwed up for so long. He’s always been wrong and now he’s fucked Dean and Cas up too.

“It’s okay, Cas. We should have healed him long before we did. I was being selfish and I hurt all of us in the process. But don’t worry, man. He’ll come around. I promise. He’s never loved anyone like he does you,” Sam confesses. And maybe he shouldn’t speak for Dean when it comes to how he feels about Cas. But Cas needs to know.

“Yes he has. He does. He loves you.”

Sam shakes his head and then remembers Castiel can’t see him. “Not like that, Cas. I’m his brother, so of course-”

“No,” Cas cuts in, fiercely, “He doesn’t love you like a brother, Sam. That’s part of the reason he feels so guilty right now. He hates himself for giving in to those desires.”

Sam doesn’t really believe it because since when is Cas an expert on human behavior? Though, Sam should probably admit that Cas knows Dean as well as if not better than Sam himself. And he’s observed humanity for years. So maybe what he says has some merit. But still…

“Cas, he feels guilty for screwing everything up with you.”

“That too,” Cas agrees, “Though I don’t know why he thinks that’s the case. I still want… and so do you. And I’m not so greedy that I have to have him all to myself. I could share.”

Sam stills, biting at his own lip in thought, “Share? Like, take turns?”

Cas nods into Sam’s chest, turning his head a little toward Sam’s body, like he needs to hide his face. As if Sam could see it anyway. Or as if there’s any reason to be embarrassed.

Sam thinks back, remembers that last time Dean had fucked him in front of Cas. The way Cas had stared at him rather than Dean. The shape Cas’ mouth formed when he came. Maybe they don’t have to share. And, just maybe, Sam is forming a plan to get Dean back in bed. With both of them, where he belongs.

“Or we could aim for a relationship with more equal footing for all of us,” Sam states, hoping Cas gets his drift. It takes a second or two, but finally, Cas nods again, a barely there bob of his head.

“In fact,” Sam continues, “I don’t see any reason to wait for Dean. And, you know, maybe if we start without him, and we’re obvious enough about it… who knows what might happen?”

Cas doesn’t breathe for almost a full minute and Sam almost takes it back. Maybe he read the situation wrong a few weeks ago. Cas might have no interest at all in being with Sam if Dean isn’t there to serve as a buffer. Except…

Sam shudders out a ragged moan when Cas works a hand under Sam’s t-shirt, fingernails scratching lightly up Sam’s abdomen. When those wicked fingers find a nipple, thumbing over it before tentatively pinching, Sam throws his head back and arches under Cas’ weight. And then Cas shifts. He swings one leg over Sam’s body and straddles his thighs, pulling both hands back enough to tug at the hem of Sam’s shirt.

After that, it’s a flurry of clothes flying and random, hot open mouthed kisses being dropped on quivering flesh. By the time they’re both naked, Sam is hard as fuck, his cock dripping all over his stomach. And Cas isn’t faring much better. He’s riding Sam’s thigh, his own cockhead bumping against Sam’s balls on every upstroke. He’s fucking pulsing and letting needy little whimpers fall out of his mouth and Sam knows he’s got to get a handle on the situation. Cas will keep going until he comes and while he doesn’t begrudge Cas an orgasm, he doesn’t want it to be over that quickly.

“Shh,” Sam whispers, hands threading through Cas’ hair and holding his head still. The calming touch makes Cas’ hips slow and then almost halt, though he still squirms every few seconds, so damn anxious. It’s fucking adorable. Cute and hot all tangled up in Sam’s mind in such a delicious way. God. Maybe he needs this as much as Cas does.

Sam pulls and brings their lips together for the first time. Cas huffs impatiently against Sam’s mouth, but when Sam rakes his tongue across Cas’ lower lip, he shatters with a soft whimper. He’s so pliant and so trusting and suddenly, despite spending weeks wishing Dean would include Cas in their fucking, he’s so glad he didn’t. This is so much sweeter for Cas’ inexperience with men. 

Flipping them with ease, Sam hovers over Cas and dives deeply into his mouth. Their tongues swirl and slide together while Cas’ hands roam freely over Sam’s heated body. And fuck if he doesn’t love the exploratory touches. It’s arousing just because it’s all so new and exciting for Cas, but also because Sam needs this. He needs to feel worshipped and loved. And he’s going to make sure Cas gets to feel the same way.

Slowly, so as not to over-stimulate the angel under him, Sam lowers himself to his forearms, planting them on either side of Cas’ head. In small increments, their bodies meet. Cas hisses when their cocks fit snugly together between their pelvises and Sam shushes him again. “Easy, Cas. Just this for now, okay? Gonna take it slow, alright?”

Cas nods and nips at Sam’s lower lip, catching it between his teeth and pulling slightly before letting it snap back into place. Sam chuckles under his breath at the petulant look Cas gives him afterward. Like he’ll take it slow, but _only_ because Sam asked nicely. And suddenly Sam kind of can’t wait until next time. There’s something very playful in Cas’ eyes and Sam thinks with just a little prodding he could bring it out. But that’s for later. Right now Cas needs to feel connected to someone. Dean really. But, in a pinch, and this is one hell of a pinch, Sam will probably do.

Ducking his head, Sam latches gently onto Cas’ jaw, teeth just barely scraping as his lips drag over the lightly stubbled skin. Cas lets out a shivering sigh and tilts his head to give Sam access to the pale line of his neck. Then there’s a hand in Sam’s hair, rubbing at his scalp and brushing sweetly through his hair and Sam smiles into Cas’ skin.

“Feels good,” he mumbles, nibbling at Cas’ ear, and Cas pulls just a little. Just enough that Sam’s hips roll down against the body under him of their own volition. And god if he can’t hear the wheels in Cas’ head turning. He’s prepared for the next tug, but that doesn’t stop him from grinding down.

“Interesting,” Cas says thoughtfully before getting a better grip on the hair covering the crown of Sam’s hair and pulling again, this time hard enough to tilt Sam’s head back and skid his own mouth across Sam’s bobbing Adam’s apple. That earns Cas several thrusts of Sam’s hips which he meets eagerly.

When Sam reminds him that they’re taking this slowly with a murmured, “Slow down, Cas. Make it last,” Cas growls, the vibrations rumbling into Sam’s skin and skidding down the length of his spine like an electric current. But he loosens his hold on Sam’s hair long enough for them to suck in several deep breaths before he pulls again.

It feels like forever they hang in that precariously balance, trading licks and kisses to each other’s throats and mouths. Cas’ rhythmic tugs at Sam’s hair take them closer and closer as Sam responds each time with a stuttering jolt of his hips. But still they linger on the outskirts of ecstasy. And it’s so fucking perfect. Sam would be content to do this all night. But Cas is getting more and more antsy, the hand he doesn’t have wrapped in Sam’s hair digging into Sam’s hip hard enough to bruise. And they’re both hot and hard, the valley between their bodies slick with both sweat and precome.

Sam knows he probably should end this, get them both off. Cas has been so damned good for him, gritting his teeth against the urge to come every time Sam presses into him. And he’s being so sweet with his little moans and mewls of encouragement. Besides, they can do this again, right? But he’s not so sure really. They didn’t necessarily come to an agreement on that earlier did they? Sam offered, but Castiel didn’t really accept.

“Cas?’ Sam starts, voice wavering and unsteady, “This a one off? Or-”

“I’d very much like this to happen again, _Samuel_ ,” For some reason, Sam shudders at the way Cas grates out his full name much like does when Dean calls him _Sammy_ , “but in order to do this _again_ we’ll have to finish the first time.”

Sam almost laughs at how pouty and sarcastic Cas sounds, but Cas’ eyes are gleaming dangerously and he’s not sure that would be safe. So he bites down on the giggle threatening to burst free and, instead, pushes down hard, dragging his dick along Cas’. But this time he doesn’t stop and Cas’ eyes go wide as he tosses his head back and keens.

And then Cas is writhing helplessly under the weight of Sam’s body. Sam’s focus narrows down to the throb of Cas’s cock against his own and the sweat slick slide of their stomachs. He feels Cas’ teeth sink into the meat of his shoulder but that’s a distant ache that pulls a groan from somewhere deep inside of him because it hurts so goddamn _good_.

When Cas comes it’s with a punched out, almost breathless, whine. He floods the skin surrounding their cocks and everything gets so much slicker and then Sam follows him right over the edge, pulsing jet after jet of come over Cas’ groin with a whimper. Tremors wrack Sam’s taut body as he fights to hold himself up over Cas, but then Cas’ hands wind around his back and pull. They end up side by side trading slow, lazy kisses as the aftershocks die down. Eventually, Sam fishes his t-shirt off the floor and cleans them the best he can. Then there are more soft kisses and aimlessly wandering hands.

Cas falls still tucked neatly against Sam, his back to Sam’s front. He fits just right as the little spoon and Sam takes his responsibility as big spoon very seriously, holding Cas tightly in the confines of his arms as he breathes deeply, perfectly relaxed. Sam knows Cas won’t sleep, but he feels fairly confident that he’ll stay while Sam does. And then, maybe round two?

**Author's Note:**

> Customary tumblr plug: Hey, if you wanna follow me on [tumblr](http://sincestiel.tumblr.com/) that would be alright. Shoot me an [ask](http://sincestiel.tumblr.com/ask) if you have a prompt (Destiel, Wincestiel, Wincest, Cockles, J2) and we'll see what happens. :)


End file.
